.bigbox{
    height: 550px;
    width: 500px;
    margin: 100px auto;
}
.bigbox .top{
    height: 50px;
    display: flex;
}
.bigbox .top h2{
    line-height: 50px;
    font-size: 24px;
    margin-left: 50px;
}
.bigbox .top h3{
    line-height: 50px;
    font-size: 24px;
    margin-left: 200px;
}
.bigbox .box{
    height: 550px;
}
.bigbox .box .list{
    box-sizing: border-box;
    height: 50px;
    border: 2px solid #000;
}